Postbiotic from Lactobacillus rhamnosus CRL1505 improves emergency myelopoiesis in cyclophosphamide immunocompromised mice

BRENDA VASILE; FLORENCIA GUTIERREZ; HÉCTOR MAXIMILIANO IVIR; ALVAREZ SUSANA; SUSANA SALVA

San Miguel de Tucuman

Congreso; LXVII Reunión Científica Anual de la Sociedad Argentina de Inmunología.; 2019

Sociedad Argentina de Inmunología (SAI)

Emergency myelopoiesis, replenishment of mature myeloid cells, proliferation and differentiation of stem cells in the bone marrow (BM), are impaired during the chemotherapy-induced myelosuppression. Lactobacillus rhamnosus CRL1505 (Lr1505) diet supplementation is an interesting alternative to improves steady-state myelopoiesis. Although the Lr1505 viability is important, it is possible to stimulate immunity by using the non-viable microorganism. In this work, we evaluated whether CRL1505 and its cell wall (CW1505) was able to improve emergency myelopoiesis induced by TLR4 agonist. Adult Swiss-mice were orally treated with Lr1505 or CW1505 during 10 consecutive days. On day 6, treated and untreated mice received one intraperitoneal dose of cyclophosphamide (Cy 150mg/kg). On day 3 post-Cy injection, mice were intraperitoneal challenged with LPS (10mg/kg weight). The inflammatory challenge induced a significant increase of the number of total, F4/80+ and Gr-1+Ly6G+ cells in the peritoneal cavity, reached a peak at 6h, and returned to the initial values at 24h post-LPS in all groups. However, mice treated with Lr1505 and CW1505 showed higher cell counts in the peritoneal cavity than the untreated CF group at 6h and 24h. Moreover, LPS reduced the number of blood and BM myeloid cells. However, the treated groups showed higher blood counts than the untreated mice at 24h post-LPS. Besides, the Lr1505 and CW1505 treatment increased significantly the LSK cells counts (Lin-Sca-1+c-Kit+) and myeloid multipotent precursors (Gr-1+Ly6G+Ly6C-) at 120h in BM. In conclusion, both L. rhamnosus CRL1505 and its cell wall were able to improve myelopiesis response against inflammatory challenged in mice undergoing chemotherapy.